Method of installing conduit

ABSTRACT

Method for installing conduit in a confined wall space are disclosed. A tape is introduced into the confined space behind the wall and is extended to an outlet point by moving a tool along the exterior wall surface. The tool has an electromagnet which attracts a metal roller on the end of the tape, drawing the roller against the interior wall surface. The tool has rollers, or wheels, allowing it to roll on the exterior wall surface, and hence the extension of the tape is by means of combined roller action on both surfaces of the wall. At the outlet, conduit is attached to the tape and is pulled into the confined space by retracting the tape. Retraction of the tape may be accomplished by a drum onto which the tape is wound.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 491,154, filedMay 4, 1983, now U.S. Pat. No. 4,527,775.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to method and apparatus for installing conduit,particularly electrical conduit, in a confined space behind a wall in abuilding or dwelling.

In new buildings or dwellings, electrical conduits are usually placed inthe wall framework before the wall panels are placed over the framework.Accordingly, the installation of conduits at this stage of constructionposes no particular problem because the space is readily accessible.However, in completed dwellings in which the wall panels have been putinto place, the installation of electrical conduit becomes a difficulttask because the conduit must be routed into blind confined spaces.Where such walls have glass fibre insulation, or other filler, in themthe task becomes especially difficult, if not impossible.

The present invention is directed to a new and improved method andapparatus for installing conduit in confined spaces behind walls whichare already in place, and which can be used where insulation, or otherfiller, occupies the confined spaces in the framework behind the walls.With the present invention, conduit can be installed in such spaces withefficiency thereby promoting increased productivity in installing suchconduit, and helping to avoid frustration during such procedures.

Briefly, according to the preferred embodiment of the present invention,a tape, commonly known as a "fish tape", is used in conjunction with amagnet. Access openings are provided to the confined space, and at oneaccess opening one end of the fish tape is introduced into the confinedspace. This end of the fish tape contains a roller which is attracted byan electromagnet which is placed on the exterior of the wall. Theelectromagnet is mounted on a wheeled carriage. When the electromagnetis energized, it attracts the roller on the end of the tape, and whenthe carriage is moved toward another access opening, it rolls the rolleralong the interior of the wall to the other point of access. At thesecond point of access the conduit which is to be installed behind thewall is secured to the end of the fish tape containing the roller. Thenthe fish tape is withdrawn, thereby pulling the conduit through theconfined space. Withdrawal of the tape, and hence pulling of the conduitthrough the confined space is accomplished by the means of a reel, ordrum, on which the tape is wound, the drum being disposed on theexterior of the confined space near the first point of access.

The foregoing features, advantages, and benefits of the invention, alongwith additional ones, will be seen in the ensuing description and claimswhich should be considered in conjunction with the accompanyingdrawings. The drawings disclose a preferred embodiment of the inventionaccording to the best mode contemplated at the present time in carryingout the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary vertical sectional view through a building, andhaving portions broken away, illustrating the principles of the presentinvention.

FIG. 2 is an enlarged fragmentary view taken in circle 2 of FIG. 1.

FIG. 3 is a fragmentary view taken generally in circle 3 of FIG. 1, butenlarged and illustrating a step in the method of the invention.

FIG. 4 is a schematic diagram illustrating structural details of aportion of the apparatus which is used in the practice of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a portion of a building or dwelling 10 and principlesof the present invention in installing electrical conduit in saidbuilding or dwelling. The building comprises an illustrativeconstruction having a vertical wall section 12, a ceiling wall section14 and an overlying roof section 16. The construction defines a roomspace 18 and an attic space 19.

For purposes of illustrating principles of the invention, the conduit isto be installed in the vertical wall section 12 to extend between theroom and attic spaces. Typical vertical wall construction comprises aseries of horizontally spaced apart vertically extending studs 20 whichare bridged along the top by means of a header 22. The illustratedheader 22 comprises two separate header members joined together. Aninterior wall panel 24, which by way of example may be drywall or lathand plaster, is secured onto the stud and header framework. Theconstruction defines a confined space behind wall panel 24 and intypical construction this space is often occupied by an insulatingmedium or other type of filler material 26 between the vertical studs.

In order to initiate the procedure for installing the conduit in wallsection 12, it is necessary to provide access openings into the confinedspace behind the wall panel 24. One point of access is provided by acutout 28 in wall 24. Typically cutout 28 will be a rectangular shapecorresponding to the rectangular shape of an electrical receptical boxwhich is to be mounted in the wall section at the opening 28. In theillustrated construction, another access opening 30 is provided throughheader 22. The latter access opening 30 comprises aligned bores in thetwo header members. A particularly suitable way for forming the bores 30is by means of the boring tool disclosed in my co-pending applicationSer. No. 231,469, filed Feb. 4, 1981. The boring tool disclosed in thatapplication is operable in the limited attic space where the roof meetsthe ceiling to permit the operator to be located in the attic space andto create the vertical bores through the headers.

Once the bores have been completed, one end of the tape 32 is introducedinto the confined area behind wall 24 through the bores 30. Tape 32,commonly referred to as a "fish tape", is preferrably coiled into areel, or drum, 34 which can be suitably positioned in the attic space ata distance spaced horizontally from wall section 12 so that the coil canbe conveniently reeled onto and off of the drum. A sheath, or guide 36may also be provided for guiding the fish tape into the bores 30.

The end of the fish tape which is introduced into the confined spacebehind wall 24 comprises a magnetic means thereon. In the illustrativeconstruction the magnetic means takes the form of a roller 38 which issuitably mounted on the end of tape 32 for rotation about its own axis39. Thus, the solid line position shown in FIG. 2 is illustrative of atypical disposition of the tape when the roller just has been introducedinto the confined space behind wall 24. If there is insulation or othermaterial in the way, the fish tape and/or sheath can be manipulated tocompact or compress the insulation to a certain limited extent.

Also associated with the invention is a magnetic tool 40. The magnetictool 40 comprises a carriage 42 containing a plurality of roller wheels44 via which the tool may be rolled along the room surface of wall panel24. Suitably mounted on the carriage 42 is an electromagnet 46. Theelectromagnet is selectively energizable to create a correspondingmagnetic attractive force which is effective through wall panel 24 todraw the roller 38 against the surface of wall 24 which is on theconfined space. Thus, the broken line position of roller 38 illustratedin FIG. 2 represents a position which the roller assumes when the toolis suitably positioned near the top of the wall and the electromagnet isenergized.

Tool 40 further comprises a handle 48 which allows the tool to bemanually grasped by an operator and rolled along wall 24. A controlswitch 50 is associated with the tool to energize and deenergize theelectromagnet. Also associated with the tool is a rheostat adjustment 52which allows the intensity of the magnetic force to be set to a desiredlevel. FIG. 4 schematically illustrates the construction and arrangementof electromagnet 46, switch 50, and rheostat 52. These are shown in aseries circuit in association with a suitable power source, for example,DC batteries 54. Alternatively, the unit could be powered by means of ACpower and a plug-in cord connected to the circuit in place of thebatteries.

When the switch 50 is closed, electric current flows from the powersource to the electromagnet to create the magnetic force. With themagnet energized, the operator rolls the tool along wall 24 towardopening 28. The magnetic force acting on roller 38 is sufficient to keepthe roller drawn against the wall to cause it to follow tool 40 rollingalong the wall toward opening 28. The rolling action, both of roller 38and of the wheels 44, facilitates the movement of both the tool 40 aswell as the extension of the tape into the confined space behind thewall panel. The roller rolls in the confined space between theinsulation filling the space and the wall surface and in so doing canpush the insulation out of the way.

The operator continues to roll the tool until the roller 38 has beenbrought to the point of access 28. The roller and the end of the tapecan then be grasped by the operator, and as shown in FIG. 3, a conduit56 which is to be installed in the wall can be attached to the tape, forexample, by means of a piece of adhesive tape 58 wrapped around theconduit 56 and the tape 32.

With the conduit 56 secured in this way to the tape 32, drum 34 isoperated to roll up the tape and thereby withdraw it from the confinedspace behind wall 24 through bores 30. For this purpose, the drum mayinclude a crank and handle 60, allowing it to be manually rotated. Thedrum is journaled on a frame which allows it to be suitably supported onthe ceiling joists at a position where it may be conveniently operated.As the tape is being retracted, the conduit 56 is drawn through opening28 and into the confined space of the vertical wall panel 24. As the endof the tape is withdrawn from bores 30, the attached end of the conduitis also drawn through the bores. The conduit has sufficient length so asto extend between the bores 30 and the opening 28 and to provide for theelectrical connections which are required. The adhesive tape 58 may nowbe removed to disconnect the end of the fish tape from the conduit. Thiscompletes the installation procedure for the conduit behind the wallpanel 24.

The rolling actions of the roller 38 and the roller wheels 44, inaddition to facilitating installation of the conduit, provide furtherbenefits. For one, the rolling action of the wheels 44 on the room wallsurface can be performed without marring the wall's appearance, providedthat the wheels are made of a suitable material such as plastic. Bymaking roller 38 of a magnetically responsive material, it is ensuredthat the roller is drawn against the inside wall surface. Otherconstructions are, of course, possible. While axle-mounted wheels for 44and 38 are shown, they could be caster-mounted, swivel mounted, or inthe nature of spherical balls suitably captured in sockets.

While the principles of the invention have been illustrated with respectto installing conduits in a vertical wall between an opening in theinterior wall surface and bores in the header of the wall section, itwill be appreciated that the principles may be applied to installingconduit in other than this type of wall between these types of accessopenings. Moreover, while the invention is particularly addressed tosolving the problem of installing conduit in a wall containinginsulation filling the interior spaces of the wall framework, it may beused where these hollow spaces are not so obstructed. The illustratedconstructions of the fish tape, and the electromagnet tool are alsoillustrative for purposes of illustrating the invention. While apreferred embodiment has been disclosed, it will be appreciated that theprinciples of the invention are applicable to other embodiments.

What is claimed is:
 1. A method for installing conduit in a confinedspace behind a wall between points of access to the confined space whichcomprises: introducing into the confined space at one point of access,one end of a tape having a magnetically responsive roller means on saidone end; said tape being coiled on a drum disposed exteriorly of theconfined space near said one point of access, magnetically attractingsaid roller means toward said wall by an attracting magnet positioned onthe side of said wall opposite the confined space; moving said magnetalong said wall to another point of access and thereby, through theattractive force of said magnet on said roller means causing said rollermeans to roll on the surface of said wall which is on the interior ofthe confined space also drawing the tape through the confined space tosaid another point of access, said tape having sufficient length toextend between said two points of access; securing conduit to said oneend of said tape at said another point of access; and turning said drumto withdraw said tape from the confined space via said one point ofaccess, thereby to draw the conduit from said another point of access tosaid one point of access.
 2. The method called for in claim 1 whereinsaid magnet is moved along said wall by rolling the magnet on a wheeledcarriage having a handle for manual grasping, the magnet being rolled byan individual user grasping said handle and rolling the wheeled carraigealong said wall.
 3. The method called for in claim 2 in which saidmagnet is an electromagnet and including a switch for operating theelectromagnet and a rheostat for adjusting the magnet intensity, saidswitch being manually actuated by the individual user to produce adesired intensity of attractive force.
 4. The method called for in claim1 in which the wall is generally vertically disposed and in which saidmagnet is moved vertically along the wall, said two points of accessbeing vertically spaced apart.